More work attempting to get the tree get/update/delete stuff working property.
Refactoring to remove the class-reference from the ACL-related
view helper. Add an explicit content type when checking for perms,
which is looked up from the class, when available, or a vertex frame
if not. TODO: Further refactoring and cleanup.

Genericised the API endpoint for setting content type permissions with
a particular scope.
Attempt to clean up ACL view and REST functions
Refactoring item/scope/global permission setting. This is the mid-
point where things look messier than they were before.
More refactoring of still-horrible ACL functions.
More refactoring, bows and arrows against the lightning edition.
Move function to helper section
Preparations for listing items
Minor cleanup.
Increase the flexibility of the API by decoupling some list functions
from the parametised class type.
Rename class and move some utility member functions to super class
Renaming params to improve clarity
Create PermissionGrant nodes the proper way so they obey serialization rules.
General refactoring of permission/acl components.
Fix tests after URL reordering
More whittling down of the hideous mess that is the ACL system.
Set item perm fetch scope correctly, and ensure AclManager scope is never null
Whoops, used wrong Optional construct to create a non-null object.
Annnd, another forgotten null check
IntelliJ analysis-derived cleanups and Eclipse imports organisation